Im having trouble with my external HDD with it not letting me save and telling me its too slow ( its 5400 rpm) . So before I go upgrade the whole thing I would appreciate any help with these ( probably) basic questions
Im using a firewire interface ( focusrite saffire) so should I daisy chain the hard drive? i.e out of the Imac - into the HDD and then out of that into the focusrite?
Is there any advantage to thunderbolt cause I was thinking of getting a thunderbolt converter and i presume I wouldn't mix up firewire and thunderbolt?
Thanks for your help
Tony

What exact model iMac do you have today? With exactly what peripherals connected to it?

The last thing to look at is a old external FireWire HDD, they belong in museums or landfills.

The best options may be a USB3 or Thunderbolt connected SSD. Lots of options there from simple USB SSDs like the Samsubg T3 up to external Thubderbolt docks with SATA or even PCIe slot or PCIe M.2 SSDs installed in them, or pre-built Thubderbolt Little Big Disk2 drives from LaCie with PCIe M.2 (if you wanted extreme performance).

The more info you can provide about your setup, including all the drives you are using for boot/system, samples and audio, your sessions (#tracks and sample rate). The more folks here will be able to give you specific advice. You do not want to be running on a 5,400 rpm drive, but Pro Tools 12 with disk cache properly enabled will tend to help a lot with many disk performance issues. still I would only look at SSDs for session drives. HDD for audio/backup drives and if needed for large sample libraries and video where SSD cost may be problematic.

Thankyou Daryl here is what I have.
Imac 21.5 late 2015 2.8 Ghz core i5 8GB 1867 DDR 3 USB 3.
Interfaces are a Focusrite safire 56 with 2 firewire 400 ports.
My session drive is a 1TB G drive with 2 firewire 800 and 1 USB 3 Im pretty sure its 5400 rpm.
I also have an old Hitachie HDD with a 80O firewire I use for backup.
The Imac has 4 USB 3 and 2 thunderbolts.
I have the G drive connected to the imac with a firewire/ thunderbolt adapter and then its daisy chained to the focusrite with a 800 to 400 lead.
The backup dive is just connected to the i mac with a firewire to thunderbolt adapter.
Seems like a mess when I write it down here.
Thing is I really only use audio and no more than 12 tracks. A little bit of midi and I dont have a separate sample drive cause I dont use them.
Im using PT 12.5 and have some basic waves plug ins. Latest version of El capitan.
Problem is bought the dam fousrite just before everything went to thunderbolt. I assume I cant mix up USB 3 with the fire wire on the fousrite. I have been wanting to change it out for a decent converter as i have my own decent pres.
I hope all this helps and I would appreciate any suggestions advice on what I should do. Cheers Tony

G-Drive? You mean G-Tech. That likely won't be a 5,400 rpm drive, it will be 7,200. What exact model is it? Go Google the model number and find out.

If its a 7,200 rpm drive and you are getting this error you should make sure the system is properly optimized and then go though the standard troubleshooting. You may be wasting your money on a new drive. But a Firewire drive is not a good idea on the firewire chain if it can be avoided, and the USB on that drive is what? USB 2? That's slow. there is also the issue of chaining sequence with the Firewire interface and drives. You should be chaining the FW400 interface off the FW800 drive, but sometimes have to also try the opposite.... or get two Apple FireWire adapters. and tun them off separate Thunderbolt busses.

These errors can also caused by too small playback buffer for the system, bad plugins, trying to run at too high a session sample rate, corrupt sessions, etc. Start with trashing prefs and looking at these things (see standard troubleshooting under the "help us help you" link up top of this web page). Do all troubleshooting with "ignore errors" *not* checked. One thing you can try as well is setting the playback engine to built-in output, disconnect the interface and rung the disk directly on the Thunderbolt to Firewire adapter and see if you still get the error. Once you have done that troubleshooting and hopefully found issues then make sure disk cache is turned on (set to a size in the playback engine dialog, start at 2GB, not set to "normal"==off).

Thanks Daryl
Youre right about the drive. It is 7200.
Its also an USB 3. So if thats the case whats the best way to join it all up? Can I go from Imac Usb3 to hard drive Usb 3 and then use the firewire 800 port on the drive to connect to the firewire interface. Or just conect then to separate buses on the I mac one usb 3 the other firewire. Ill do all the trouble shooting stuff too.
I appreciate your help.
Cheers Tony

or get two Apple FireWire adapters. and tun them off separate Thunderbolt busses.

+1
Thatīs always a good idea just from experience.
Get another Firewire-to-Thunderbolt-Adapter and connect your Saffire to one TB port (put a FW800-to-FW400 adapter cable into the
FW-to-TB-adapter), your Hitachi HDD to the 2nd one for backups.
From my personal experience decent quality FW800-to-FW400 adapter cables do work better with interfaces than those connector plugs. http://www.amazon.com/Citi-Electroni...0+to+400+cable

Then connect your Session drive to one of your USB 3 ports, just make sure you have a new, good quality USB 3(!) cable (sometimes
people just use standard USB 2 cables for USB 3 drives which will not provide the desired increase in speed and stability finally).
This will speed up your session drive a lot (and solve the issue if itīs coming from a defective FW cable or FW port)!
As for speed a 7200rpm HDD via FW800 runs at about 60-80mb/s Write/Read at the max, the same 7200rpm HDD via Thunderbolt/USB 3
goes with about 160-170mb/s. Thatīs quite a difference in speed actually.

Btw no, you canīt mix USB 3 and Firewire within a chain.

Like Darryl already mentioned there might be other reasons for your errors. He has covered it all obviously.
If trouble shooting will not bring the desired success I would advice to (Iīm aware of that people donīt like this advice a lot) back up all
your stuff first and then do a complete clean install of your whole system. This often is the best solution finally.

This one got really good converters for the price and itīs Thunderbolt connected which would perfectly suit your 2015 iMac. Offering the
lowest latency on recording on the market and 8 ADAT inputs obviously.

About 380-400mb/s Write/Read and definitely reliable enough for the work with PT12. Pretty nice for the price actually.

Again, if you cannot solve the issues by trouble shooting and reconnecting your external devices (check all your cables as well!), do yourself
a favor and perform a clean install of your system including setting up all the optimizations in your OSX before installing PT.http://avid.force.com/pkb/articles/t...Optimize-10-11
This might help to solve it finally.

Thanks Daryl
Youre right about the drive. It is 7200.
Its also an USB 3. So if thats the case whats the best way to join it all up? Can I go from Imac Usb3 to hard drive Usb 3 and then use the firewire 800 port on the drive to connect to the firewire interface. Or just conect then to separate buses on the I mac one usb 3 the other firewire. Ill do all the trouble shooting stuff too.
I appreciate your help.
Cheers Tony

Well 7,200 rpm and USB3 changes everything. You should be running that drive off USB3 now, and your interface off a Thunderbolt to FireWire adapter. The drive does not/can not convert USB3 to FireWire (no peripheral can).

Start there, if that does not immediately fix things you likely have a totally different configuration, optimization, or software problem not related to the drive (even if you get errors saying the drive is too slow).

Thanks Daryl and VRW i have changed the connections as advised and cleaned up prefernces as well. So far so good. There is certainly some good help to be had on this site. I should have read the help us help you site first. Cheers Tony
The

The last thing to look at is a old external FireWire HDD, they belong in museums or landfills.

Don't get me wrong Darryl, I wouldn't advocate anyone with a non-FireWire equipped computer buying into FireWire as a protocol nowadays, but I think it's a little harsh to say they only belong in museums and landfill.

They are capable of delivering enough throughput for most people's needs.

I've recorded 48 tracks at once, and at mix time I've had more than 100 tracks playing back without any complaints from the FireWire drive or the computer trying to suck data off it.